In the hands of the canniest opponents, a strength can become a weakness. Only Barcelona in Europe's top five leagues have better possession and pass completion rates than Bayern Munich this season and so the dynamic of the game was always likely to be similar to Chelsea's semi-final against Barcelona: Bayern had the bulk of possession; Chelsea, through weight of numbers in deep positions, tried to frustrate them.

Yet Bayern pose a very different sort of threat to Barcelona. Barça tend to build through the middle, all short sharp passes and little darts of acceleration; Bayern are more traditional, playing with wingers who start wide and drift infield, with overlapping full-backs looking to get in positions to cross for Mario Gomez, a centre-forward who, with his bulk and questionable touch, is almost a typical English No9.

In Bayern's 5-2 defeat to Borussia Dortmund in last week's German Cup final, it was notable how Dortmund targeted the way Bayern's full-backs, Philipp Lahm and David Alaba, push high up the pitch. The plan was clear: get the ball to Shinji Kagawa and have the two wingers Kevin Grosskreutz and Jakub Blaszczykowski sprinting beyond the full-backs.

The ploy, performed successfully, can be doubly effective. Not only do the wingers exploit the space behind the full-backs, but it also affects the opponent from an attacking point of view as the full-backs become wary of pushing on too far for fear of getting caught on the counter.

Chelsea's method of dealing with the wide threat could hardly have been more different; rather than trying to hit that space behind the full-backs, they went for placing a double barrier in front of them, with Ryan Bertrand effectively an auxiliary left-back and Salomon Kalou, although more attacking, clear under instruction to support José Bosingwa as much as possible.

With Alaba one of three suspended players for Bayern, Diego Contento came in at left-back despite having made just five starts in the Bundesliga this season. Perhaps understandably, Contento looked edgy early on, slicing one clearance high into the air, but he soon settled and Bayern, for much of the first half, looked more dangerous on their left than on the right, perhaps precisely because Kalou interpreted his wide midfield role rather more liberally than Bertrand did on the other flank.

Jupp Heynckes, the Bayern manager, had had the option of moving Lahm to the left to bring in Rafinha – with 20 Bundesliga starts this season – at right-back, but opted to preserve the link-up between Lahm and Arjen Robben that has been one of the keys to Bayern over the past couple of years. In the first leg of the semi-final against Real Madrid it was their domination of that flank against Fábio Coentrao and Cristiano Ronaldo, aided by the performance of the central midfield, that gave Bayern the edge, culminating in the late winning goal, bundled in by Gomez after Lahm's overlap and cross.

This was very different to the Real Madrid games, though, because Chelsea were so much more reactive. Whereas Madrid had always kept at least four players upfield, with Ángel di María shuttling back, Chelsea's 4-2-3-1 often became a 4-4-1-1, and that meant there was rarely space for either Lahm or Contento to advance into.

Bosingwa, always more comfortable on the ball than when having to defend, had a distinctly awkward first half. A Contento dart outside Franck Ribéry after 14 minutes distracted the Portugal international sufficiently to create space for a cross, but Gomez headed over.

A similar dummy run from the full-back 20 minutes later again drew Bosingwa away, but Ribéry, cutting infield, dragged his shot wide.

When Lahm first broke through at Bayern, his constant running earned him the nickname Wireless-Lahm (a play on Wireless-LAN) from team-mate Mehmet Scholl, but he had few opportunities to show that here. There were a couple of sallies early in the second half, but for the most part as soon he got going, he found blue shirts waiting for him.

As Dani Alves had in that second leg in the Camp Nou, Lahm again and again found himself with the ball but without momentum, unable to burst into the space behind his opposite number because there was no space behind him.

That is what Athletic Bilbao's coach, Marcelo Bielsa, means when he speaks of "vertical penetration" and it is what Chelsea's deep double protects against.

In the end, though, it was the flank that provided the breakthrough – on the Bayern left, where Chelsea had looked so vulnerable in the first half. Put over enough crosses and, eventually, the chance will come. This time the overlapping run was by Bastien Schweinsteiger, who cut the ball back for Ribéry; his inswinging cross may have been intended for Gomez but it found Thomas Müller, whose downward header bounced by Petr Cech.

And after the equaliser, it was the flank that should have given Bayern the lead again as Ribéry drifted in from the left and was tripped by Drogba. But essentially, Chelsea did enough to check Bayern on the flanks: they might not have used that strength against Bayern as Dortmund did, but they stopped their opponents from fully exploiting it.